package first.endtoend;

import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.util.Log;


public class GPSTracker extends Service implements LocationListener{
	
	private final Context mContext;
	
	//flag for GPS status
	boolean isGPSEnabled = false;

	//flag for network status 
	boolean isNetworkEnabled= false;
	
	boolean canGetLocation= false; 
	
	Location location; 
	double latitude;
	double longitude; 
	
	//the minimum distance to change updates (in meters) 
	private static final long MIN_DISTANCE_CHANGE_FOR_UPDATE=10; //10 meters
	
	//the minimum time between updates (in milliseconds) 
	private static final long MIN_TIME_BTWEEN_UPDATES= 1000*60*1; // 1 minute
	
	//Declaring a Location Manager
	protected LocationManager locationManager; 
	
	
	public GPSTracker(Context context){
		this.mContext=context;
		getLocation();
	}
	
	public Location getLocation() {
		// TODO Auto-generated method stub
		try{
			locationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE);
			
			//Getting gps status
			isGPSEnabled= locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
			//Getting network status
			isNetworkEnabled= locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
			
			if(!isGPSEnabled && !isNetworkEnabled){
				System.out.println("none of the providers is enabled");
			}else{
				this.canGetLocation=true;
				
				//get location from Network provider 
				if(isNetworkEnabled){
					locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,MIN_TIME_BTWEEN_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATE,this);
					Log.d("Network", "Update location from Network provider");
					if(locationManager != null){
						location=locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
						if(location!=null){
							latitude=location.getLatitude();
							longitude=location.getLongitude();
						}
					}
				}
				
				//if the GPS is enabled get lat/long using GPS services
				if(isGPSEnabled){
					if(location==null){
						locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME_BTWEEN_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATE, this);
						Log.d("GPS", "Update location from GPS provider");
						if(locationManager != null){
							location= locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
							if(location!=null){
								latitude=location.getLatitude();
								longitude=location.getLongitude();
							}
						}
					}
					
				}
			}
		}
		catch (Exception e){
			e.printStackTrace();
		}
		
		return location;
		
	}

	@Override
	public void onLocationChanged(Location location) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void onProviderDisabled(String provider) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void onProviderEnabled(String provider) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void onStatusChanged(String provider, int status, Bundle extras) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public IBinder onBind(Intent intent) {
		// TODO Auto-generated method stub
		return null;
	}
	
	/**
	 * Function to get latitude
	 * */
	public double getLatitude(){
		if(location != null){
			latitude=location.getLatitude();
		}
		return latitude; 
	}
	
	/**
	 * Function to get longitude
	 * */
	public double getLongitude(){
		if(location != null){
			longitude = location.getLongitude();
		}
		return longitude;
	}
	
	/**
	 * Function to show settings alert dialog 
	 * */
	public void showSettingsAlert(){
		AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
		alertDialog.setTitle("GPS settings");
		alertDialog.setMessage("GPS is not enabled, do you want to go to settings menu ?");
		alertDialog.setIcon(android.R.drawable.ic_dialog_alert);
		
		// On pressing Settings button
        alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int which) {
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                mContext.startActivity(intent);
            }
        });
  
        // on pressing cancel button
        alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();
            }
        });
  
        // Showing Alert Message
        alertDialog.show();
	}
	
	/**
     * Function to check GPS/wifi enabled
     * @return boolean
     * */
    public boolean canGetLocation() {
        return this.canGetLocation;
    }

	/**
     * Stop using GPS listener
     * Calling this function will stop using GPS in the app
     * */
    public void stopUsingGPS(){
        if(locationManager != null){
            locationManager.removeUpdates(GPSTracker.this);
        }      
    }
}
